In-vitro and in-vivo metabolic studies of corneal tissues are proposed using a non-invasive spectrofluorometric method. Measurements of the concentrations of the naturally fluorescent pyridine nucleotides and flavoproteins will be performed and will be related to the active transport properties of the normal and pathological cornea. These methods should allow the determination of the tissue oxygen tension, of the mitochondrial function and of the metabolic state of the different corneal layers in the living tissues. The proposed method could subsequently be applied to assist in clinical diagnosis, evaluation and treatment of corneal disease. These procedures will include the use of modified specular microscopes and time-sharing fluorometers. Metabolic parameters will be studied in perfused corneas in-vitro, in-vivo corneas, suspensions of mitochondria from the different corneal layers and in freeze-trapped corneal sections. This project is possible through the collaboraton of three different laboratories who have joined their effort for this goal.